Drill



H. BEHNAY.

DRILL.

APPLICATION FILED FEB 0 APR. 6, I920. 7 1,355,793. Patented Oct.12,1920.

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F M... W W/ H a? K We 2 2 u. m mm fl 1 rM ll. 5 6 4/ UNITED STATES HENRIBERNAY OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGN- PATEINTOFFICE.

MENTS, TO FRED W. THURSTON, OF SAN FRANCISCO, CALIFORNIA.

DRILL.

Specification of Letters Patent. Patented O t. 12 1920 Application filedFebruary 24, 1919, Serial No. 279,001. Renewed April 6, 1920. Serial No.371,738.

To all whom it may concern:

Be it known that I, .IIENRI BERNAY, a citizen of the United States,residing in the city and county of San Francisco, State of- California,have invented a new and useful Improvement in Drills, of which thefollowing is a specification.

The present invention relates to improvements in rock drills and thelike wherein a detachable bit operates in conjunction with a slottedstock to prevent splitting of the stock when a pressure is applied tothe cutting edge of the bit.

The primary object of the present inven' tion is to provide an improvedrock drill havin a detachable bit.

A Eurther object of the invention is to provide a device of thecharacter described having improved means for attaching a bit to aslotted stock in such a manner that a pressure applied to the cuttingedge of the bit will tend to move the portions of the stock beyond theslot toward each other and thereby prevent splitting of the stock.

A further object of the invention is to provide improved means forsecuring a bit within a slotted stock, said means being adapted tofacilitate the insertion and removal of the bit.

Other objects and advantages-will here-. inafter more fully appear.

. I accomplish these several objects by means of the improved devicedisclosedin the drawings forming a part of the present specificationwherein like characters of ref erence are used to designate similarparts throughout the said specification and drawings, and in which: dIiigure 1 is an elevation of my improved ri l;

Fig. 2 is a side elevation of Fig. 1;

Fig. 3 is a vertical sectional view taken on I line 33 of Fig. 2 in thedirection indicated;

Fig. 4 is a bottom view ofFig. 1;

Fig. 5 is atop plan view of a bit removed from the stock; A

Fig. 6 is a front elevation of Fig. 5;

Fig. 7 is a bottom view of the stock with thebit removed; and

Figs. 8 and 9 are an elevation and bottom view of a modified form ofbit.

Referring to the drawings the numeral 1 is used to designate a stockbored centrally as at 2 and provided with a centrally disposedtransverse slot 3 whose walls converge toward the end of said stock 1.The ends of the stock 1 beyond the open end of the slot 3 are beveledanddiverge from said slot 3 toward the sides of the stock 1 as at 4.

The stock 1 is also provided with annular slot 3, the purpose of whichwill after he more fully set forth.

A b1t 7, provided with at "least one transhereinverse" cutting edge 8,has beveled surfaces 9 to engage the bevel surfaces 4 of the stock:

- a pressure is applied to the cutting edge8 the inner end of theextension 11 will not be forced against the inner end of the said slot3, to prevent splitting of the stock 1.

As the slot 3 is narrower at its outer end the shape of saidslot willprevent a longitudinal movement of the extension 11 of the bit 7 withinsaid stock 1.

The extension has formed on its sides recesses 12 which re ister withthe annular grooves 6 in the stoc l.

Rings 14 are rotatably mounted within the grooves 6 and recesses 12 whenthe beveled surfaces 9 and 4 are in engaging relation. Each ring 14 isprovided with a gap 16 smaller than the width of the slot 3, the ends ofsaid rings 14 being beveled as at 17 to facilitate insertion and removalof the extension 11 within the slot 3 when removing or inserting a bit.1

The bit .7 is bored transverselyas at 18 andhas a longitudinal bore 19through the cutting edge 8 and. intersecting the first mentioned bore18. The surfaces'of the extension 11 are provided with recesses orgrooves 21 which operate in conjunction grooves 6 arranged between theends of the with the central bore 2 of the stock 1 to pro- I vide apassage for water when drilling.

To remove the bit the gaps 16 in both rings 14 are moved to registerwith either end of the slot 3. As the gaps 16 in said rings 14 areslightly smaller than the width or thickness of the extension 11 it isevident that said rings 14 will still prevent a movement of saidextension 11 within the slot 3.

But, by applying a slight pressure of the end of the extension 11against the beveled ends 17 of the rings. 14 said rings will be slightlyexpanded to increase the width of the gap to an extent sufiicient topermit the passage of the extension 11 through said gaps.

' In replacing a bit the end ofthe extension is similarly pressedagainst the beveled ends 1. 17 of the rings 14 to expand said rings anextent sufiicient to permit the entrance of said extension 11.

The probability of both gaps inadvertently registering with the same endof the slot 3 simultaneously when said gaps have been spaced apart isexceedingly remote, and should the condition occur it is. evident thatthe gap 16 would be insufficient for the passage of the extension andthe bit would be retained in position.

In operation, when a pressureis applied to the cutting edge'8 of the bitsuch a pressure is transmitted to the beveled surfaces 9 of said bitwhich engage the beveled snr-' faces4 beyond the open end of the slot 3of the stock 1 and tend to move said ends toward instead of away fromeach other thereby tending to prevent splitting the stock 1. In Figs. 8and 9 of the drawings, I have disclosed a modified form of bit 7provided with two cutting edges 8' in the well known cruciform typewhich may be used advantageously with the drill.

5 Having ,thus described my invention, what -I claim as new and desireto secure by Let- .ters Patent, is

1.'A drill comprising a stock having a transverse slot therein, thewallsof said slot converging toward the end of the stock; a bit having aextension shaped to fit the slot and detachably engaging said slot andrings rotatably mounted upon the stock and the extension and having gapstherein, said gaps being smaller than the thickness of the bitextension.

2. A drill comprising a stock having a.

transverse slot therein; a bit having at least one cutting edge and anextension shaped to fit the slot, said bit being arranged to en- 'gagethe ends of the stockon each side of I the slot and tend to move saidends toward each other when a pressure is applied to the cutting edge ofthe bit to prevent splitting of thestock; and rings rotatably mountedupon the stock and bit extension, said rings having a gap thereinslightly smaller than the width of the extension.

3. A drill comprising a stock having transverse slot therein; the endsof the said stock beyond the slot being beveled; a bit havingat leastone cutting edge and an extension shaped to fit the slot and beveledsurfaces to engage the bevel ends of the stock and tend to move saidends toward each other when a pressure'is applied to the cutting edge ofthe bit whereby splitting of the stock may be prevented; and ringsrotatably mounted upon the stock and the extension of the bit to preventa movement of the extension Within the slot and thereby secure the bitto the stock, said rings each having a gap therein of smaller width thanthe width of the extension.

4. A drill comprising a stock having a transverse slot therein; a bithaving an extension mounted within the slot; and rings rotatably mountedaround the stock and bit extension to prevent a movement of saidextension within the slot, said rings each having a gap therein smallerthan the width of the extension and provided with beveled ends tofacilitate the removal and insertion of said extension within said slot.

5. A drill comprising a centrally bored stock having a transverse slotthereininterseoting said central bore; a bit having a cutting edge andan extension arranged to engage the slot, said extension being boredlaterally and provided with grooves on each face of the extension andcommunicating with said bore, and a second bore through the body andcutting edge of the bit communicating with the first mentioned bore; andmeans for preventing a movement of the extension within the slot.

, 6. A drill comprising a centrally bored stock having a transverse slottherein inter- 2 laterally and provided with grooves on each face of theextension and communicating i with the said bore, and a second borethrough the body and cutting edge of" the bit com- -municating with thefirst mentioned bore;

and rings rotatably mounted upon the stock and the extension of the bitto secure the bit to the stock, said rings each having a gap thereinsmaller than the width of the s ot.

7. A drill comprising a stock having a transverse slot therein, thewalls of said slot-converging toward the end of the stock and the endsof the stock being beveled in opposite directions on each side of theopen end of the slot; a bithaving at least one cutting edge and beveledsurfaces to engage the beveled ends of the stock whereby a pressureapplied to the cutting edge of the bit will cause said surfaces to tendto move said beveled ends toward each other and thereby preventsplitting of the stock, said bit being provided with an extension shapedto fit the slot but of a shorter length than said slot whereby nopressure will be applied by the end of the extension onto the inner endof the slot; and means for preventing a movement of the extension withinthe slot.

a 8. A drill comprising a stock having a transverse slot therein, thewalls of saidslot converging toward the end of the stock and the ends ofthe stock being beveled in opposite directions on each side of the openend of the slot; a bit having at least one cutting edge and beveledsurfaces to engage the beveled ends of the stock whereby a pressureapplied to the cutting edge of the bit will cause said surfaces to tendto move said beveled ends toward each other and there- -by preventsplitting of the stock, said bit being provided with an extension shapedto fit the slot but of a shorter length than said slot whereby nopressure will be applied by the end of the extension onto the end of theslot; .and rings rotatably mounted upon the stock and extension toprevent a movement of said extension within the slot, said rings havinga gap therein smaller than the.

width of the slot and beveled ends adjacent said gapto facilitateremoval and insertion of the extension when said gaps register with theslot.

9. A bit having a transverse cutting edge and a reduced extensionsubstantially rec-.

tangular in cross section and provided with looking recesses in each endof said extension, said bit being bored transversely through saidextension and longitudinally through the cutting edge to the firstmentioned bore.

10. A bit having at least one transverse cutting edge and a reducedextension narrower in width than the length of said cutthe bit and boredtransversely and likewise bored through the cutting edge to the firstmentioned bore, and grooves on each face of the extension alsocommunicating with said first mentioned bore, and having beveledsurfaces converging from the sides of the bit to the base of theextension, and looking recesses formed in the sides of the extension vand at right angles to the cutting edge. v

In witness whereof, I hereunto set my signature.

I-LENRIdBERNAY.

